It is as if all the work of several years, the decisions taken and the impact on the public is distilled into a few hours when the electorate passes its verdict.
For those whose names are actually on the ballot papers, it can be a moment of defining personal fulfilment. Or loss.
Of course there are local trends which reflect specific issues or campaigns but there are occasions when you recognise that there has been a national era-changing shift.
This past week, the 25th anniversary of the Labour victory in 1997 brought back memories for many of us who shared that electric charged evening when the electorate slammed shut the door on nearly two decades of Tory rule.
For me, the moment was best captured by my life-long Conservative Mum who, babysitting for us overnight, was waiting for me when I came back from reporting on Anne McGuire’s victory for Labour in Stirling. I was surprised when she greeted me with a huge smile and said: “What an evening. It was time for change.”
I thought about her on Friday and, although council elections tend not to generate the same excitement, I thought she might have seen this as one of those moments.
All across the country people were saying: “Enough.”
After a long day campaigning in Edinburgh West on Thursday, I got up to the news that the Liberal Democrats in England were proving major beneficiaries of a Tory collapse in their traditional blue wall seats in the south.
The Westminster by-election victories in Chesham and Amersham and North Shropshire were being replicated in councils in every English region.
But it was when I arrived at the Edinburgh Council count that I really began to experience that feeling of change afoot. For the past decade or so, we have become used in Scotland to every election being reduced to a battle between two nationalisms, with the Conservatives casting themselves in the main unionist role.
Not this time. What was happening in Edinburgh, and reflected in messages coming in from across Scotland, was a very different picture and one which matched the shift in England in scale and consequence for the Conservatives.
Early predictions that they would lose their place as second largest party in Scotland’s councils began to look kind as we watched longstanding and, in most cases, hard-working councillors lose their seats.
Victims of the disillusion and anger we had heard on doorsteps over the previous few months.
As the pandemic abated and normality beckoned, frustration at the Prime Minister and his immediate entourage increased.
It wasn’t just Partygate however, but a growing belief that the Cabinet as a whole seemed completely out of touch with the reality for most families and pensioners in this country.
At door after door, in ward after ward, voters told me they wanted something different from the current offering from Downing Street. And it wasn’t that they wanted independence, just a different government. One that listens.
And while these elections did not offer that opportunity, they did allow the electorate to send a clear and unequivocal message to Boris Johnson.
For too long they have had to put up with a government more interested in spin than substance.
None of us doubts the importance of furlough in helping millions cope with the financial impact of lockdown, but what has followed has been unforgiveable.
Millions of pounds of tax-payers’ money abandoned to fraudsters by a government seemingly more concerned with giving tax rebates to bankers than helping pensioners heat their homes or families feed their children.
And as energy prices rocketed and the Ukraine war put even greater strain on gas supplies, the Prime Minister’s attempt to look Churchillian could not deflect from his failures at home.
No speech to any war-torn country, however much public support might be behind its embattled population, can mitigate the failure of a government whose pensioners will spend the day on a public bus because they cannot heat their home.
If the Prime Minister were in any doubt, Friday has surely provided him with the proof of what we already knew.
The question for Conservatives, of course, is what now? Is there a way back from this brink? For months, I have been calling for policies that tackle the cost-of-living crisis.
No more silly suggestions about value brands, or loaning tax-payers their own money so they can pay their heating bills. Or a National Insurance hike and stealth taxes.
Instead we need VAT cut from 20 to 17.5 per cent to reduce prices and alleviate the burden on hard-pressed families. And we need a one-off windfall tax on the super profits of energy companies to help cut domestic heating bills.
It is the failure of the Prime Minister and his Chancellor to listen to these and other calls which led them to defeat at the council elections.
In cities like Edinburgh, people are calling for, and deserve better than what the two most powerful men in the country have offered.
The message they have been sent was loud and clear. And it echoed from the Highlands to the southern most parts of England.
It is, as my mother would have said, time for change.
Christine Jardine is the Scottish Liberal Democrat MP for Edinburgh West